Body fat calculator
Body fat from your waist, neck and hip measurements, with the US Navy method. All you need is a tape measure.
Measure the neck just below the larynx, the waist at the navel for men or at the narrowest point for women, the hips at the widest part of the glutes. Keep the tape level and do not suck in.
Track it every day in the app
In Gloox you can also estimate body fat from a photo: attach it to a measurement and the coach estimates your body fat and compares it with the last photo.
On a computer? Point your phone's camera here to get the app.
How the US Navy method works
The formula links body fat to the neck and waist (plus hips for women) and height. The military uses it for regular fitness checks: it is simple and usually within 3–4 % of a scanner reading.
Body fat ranges
For men, fitness is 14–17 % and average 18–24 %. For women, fitness is 21–24 % and average 25–31 %. Competing athletes go lower, but that is hard to hold for long.
Tracking change
Measure every 1–2 weeks at the same time, ideally in the morning. The trend matters more than one reading: a shrinking waist at a steady weight means fat is going and muscle is coming.
Questions
How accurate is it?
About 3–4 % off a DEXA scan. Good enough to follow progress, as long as you measure the same way each time.
Why do women need a hip measurement?
Women tend to store more fat on the hips and glutes, so without it the formula would read too low.